Probation, police and prison authorities were warned of the risk a serial rapist posed eight years before he carried out a sex attack spree, an official review found.
Joseph McCann was handed 33 life sentences and jailed for a minimum term of 30 years in December for the string of attacks on 11 women and children last year.
But officials were warned as early as 2011 that he had the hallmarks of a sex offender - and later probation officers missed eight chances to keep him behind bars, according to the report from the Ministry of Justice (MoJ).
Described by his sentencing judge as a "classic psychopath", the 34-year-old convicted burglar had been freed after a probation service error two months before he embarked on the cocaine and vodka-fuelled rampage.
The review, published on Thursday, said at a meeting of police, probation and prison officials in 2011, "police shared information which dated back to 2003 suggesting McCann might pose a risk of sexual harm and exploitation to teenage girls".
Alan Collins, one of the lawyers representing McCann's victims, said: "It's horrific to think that all of this was completely avoidable.
"They placed McCann's interests ahead of those of the general public."
Prison staff also intercepted two sets of letters from McCann, with "disturbing contents and one of the letters was addressed to his offender manager".
Some of the contents "indicated he posed a risk of sexual harm" and a number of psychological assessments were carried out on him.
Probation staff repeatedly failed to recall serial rapist Joseph McCann to prison despite concerns being raised by other officials, the report also found.
The findings have prompted the MoJ to ask chief inspector of probation, Justin Russell, to carry out an independent review of the National Probation Service's management of McCann and how the process of recalling offenders to prison is working.
CCTV of serial rapist Joseph McCann at a Morrisons in Greater Manchester where he abducted a 71-year-old woman (Metropolitan Police/PA)
McCann had a string of convictions in the North West and South East of England, having received his first term behind bars at the age of 15.
While he had no convictions for sexual offences, he did have a history of violence and threats towards his partners.
Crimes included escaping custody by grabbing and threatening a female security guard with a plastic knife, possessing a blade, robbery and two burglaries.
When McCann broke the law again while out on licence in 2017, he should have been recalled to prison under the terms of an indeterminate sentence for the public protection (IPP) - which he was handed in 2008 after admitting burgling the home of an 85-year-old man.
This would have ensured the Parole Board had to decide whether he was safe before his release.
Instead, he was automatically freed from jail after serving a fixed prison term - known as a standard determinate sentence.
Since his release in February 2019, McCann was seen by probation officers 10 times in two months.
The last occasion was on April 19, three days before he carried out his first rape.
Over 15 days, he abducted, raped and assaulted victims aged between 11 and 71 in Watford, London and the North West.
A jury found him guilty of 37 charges relating to 11 victims, including eight rapes, false imprisonment and kidnap.
The findings of the MoJ's internal investigation - known as a serious further offence review - are not routinely published but the department, which is responsible for probation, came under pressure to do so in this case.
The report criticised a lack of "exploration of sexual deviance" in McCann's case, saying: "The pertinent risk concerns of the case were lost in the numerous handovers between offender managers, as well as failures to comprehensively consider historical intelligence."
It added: "It appears that the pressure on the staff throughout 2018 and the chaotic transfer of the case between numerous offender managers also significantly impacted their ability to comprehensively review McCann's historical record, and therefore to identify the previous references to sexual violence.
"Had offender managers reviewed the historical records, including the police intelligence, they might have instigated one to one work with McCann to address sexual violence.
"However, aside from this historical intelligence from 2003 and the letters intercepted by the prison in 2009, there were no more recent indicators of concerning sexual behaviour, and this failure should be viewed in this context."
According to the report, the "most significant failing" by the National Probation Service's South East and Eastern division was the "repeated failure to recall Joseph McCann or to reflect critically on earlier decisions not to recall him, in the face of both court and prison staff communicating their concerns.
"From the point where McCann was arrested for burglary in 2017 to the point of his release, there were eight occasions where recall was considered or the recall decision was questioned.
"These all represented opportunities to recall.
"If the probation service had recalled McCann he would not have been released until the Parole Board was satisfied his release could be managed in the community."
Of four probation staff who were directly involved in McCann's case, one was demoted.
An earlier investigation resulted in one member of staff involved with McCann being dismissed and an agency worker's contract being terminated for "poor performance", although it was not thought to be directly related to the case.